fix lazynode diff bug adding children

packages/core/src/diff.rs

@@ -424,6 +424,7 @@ impl<'b> DiffState<'b> {
             (0, 0) => {}
             (0, _) => {
                 let created = self.create_children(new.children);
+                self.mutations.push_root(root);
                 self.mutations.append_children(created as u32);
             }
             (_, _) => self.diff_children(old.children, new.children),